This invention concerns releasable connections for attaching one part to another. Releasable connections for attaching one part to another most commonly involve the use of threaded fasteners passing though one part and received in threaded holes in the other part.
When connecting molded plastic parts where high strength is required, metal screws cannot be directly received into threaded holes in the plastic material, but metal inserts must be installed in enlarged bores in one part and secured therein, as by heat staking. Threaded bores in the inserts receive the attaching screws.
The process of installing the inserts, and the cost of the inserts themselves can add to the cost of production, which costs are particularly significant where large production volumes are involved. In situations where the production is automated, complex equipment is required to accurately locate and form the bores for the inserts and secure the inserts as by heat staking, resulting in substantial capital expense for the manufacturer.
In the automotive industry, automated production is used to the maximum extent possible, and molded plastic composite materials are increasingly used in order to save weight for such parts as engine intake manifolds, which were formerly made of cast aluminum.
Fuel delivery systems for automotive engines are becoming more sophisticated, involving the use of functional components in the intake manifold cavities, which components must be accessible for servicing. Thus, covers have been proposed to be releasably attached to close openings in the intake manifold so as to enable removal of internal components.
In such applications, it would be highly desirable to releasably attach the cover without the necessity of installing inserts in the composite material.
Accordingly, it is an object of the present invention to provide a releasable connection which does not require threaded fasteners, and which is particularly adapted to securely attach molded parts together at low, such as a cover for a molded composite plastic intake manifold.